Effects of Milk Replacer Supplementation with Beta-Glucans on Male Dairy Calf Performance

The objective of this randomized controlled trial was to determine the performance effects of milk replacer supplemented with a feed additive high in beta-glucans for male dairy calves. Holstein male calves (n = 147) were enrolled in a 76-day randomized block trial in two blocks. Upon enrollment, calves were assigned to one of the four following treatments: Control with no beta-glucan supplementation (BG0; n = 36; BW = 48.32 ± 3.73 kg), 1 g· animal-1· d-1 (BG1; n = 38; BW = 48.29 ± 2.89kg), 3 g· animal-1· d-1 (BG3; n = 37; BW = 48.31 ± 3.23 kg), and 5 g· animal-1· d-1 (BG5; n = 36; BW = 48.47 ± 3.00 kg) of beta-glucans. The beta-glucan supplement was blended with milk replacer (24% CP, 20% fat; 130 g/L) and fed to calves during the morning milking. Calves were individually housed, had unlimited access to water, and a pelletized calf starter (20% CP). Calves were fed 5 L/d of milk replacer divided into two equal meals until d 15; milk feeding plan increased until d 35 (8 L/d), on d 36, milk allowance was gradually reduced until weaned on d 56 (2.5 L/d). Calf starter intake and body weight were recorded weekly until d 77. Disease treatment was recorded daily. A mixed linear model determined the effect of treatment on calf starter intake and average daily gain. The model included treatment if the calf was ever treated with antibiotics for respiratory disease and/or diarrhea, study period, and a treatment by period interaction. Block was considered a random factor. The total milk replacer intake was 5.73 ± 0.08, 5.71 ± 0.08, 5.73 ± 0.01, 5.73 ± 0.01 L/d for BG0, BG1, BG3 and BG5, respectively. Calf grain intake by treatment was 58.10 ± 12.02, 54.58 ± 8.11, 56.86 ± 11.8, 56.73 ± 15.52 for BG0, BG1, BG3 and BG5, respectively. Overall, 55% and 71% of all calves were treated at least once for diarrhea, and respiratory disease respectively. The percentage of animals treated for diarrhea by treatment were 45.00, 57.50, 50.00, and 32.50% for BG0, BG1, BG3, and BG5, respectively. For respiratory disease, the percentage of animals treated was 72.5, 72.5, 70.0, and 70.00 for BG0, BG1, BG3, and BG5 treatments, respectively. There was a significant interaction between treatment and study period where the control group had greater starter intake during the postweaning period (BG0 = 0.78 ± 0.01, BG1= 0.82 ± 0.01, BG3 = 0.81 ± 0.02, BG5 = 0.82± 0.01 kg/d; P < 0 .001). No treatment or treatment by study period effects was observed for average daily gain (P = 0.79, P = 0.89, respectively). Future research should investigate the effects of beta-glucans on blood metabolites and palatability throughout the calf-rearing period.